refactor: DuplicateRequestLimiter and ratelimit

src/main/java/com/laker/admin/module/ext/controller/ProductController.java

@@ -0,0 +1,40 @@
+package com.laker.admin.module.ext.controller;
+
+import cn.dev33.satoken.annotation.SaIgnore;
+import com.laker.admin.module.ext.service.ProductService;
+import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.tags.Tag;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+@Tag(name = "△△△4.电商△△△")
+@RequestMapping("/product")
+@RestController
+public class ProductController {
+
+    @Autowired
+    private ProductService productService;
+
+    /**
+     * 抢购商品
+     * 运用工具（像 Postman 或者 Apache JMeter）模拟多个线程同时访问 /purchase/{productId} 接口。
+     * 当多个线程同时抢购商品时，就可能出现超卖的情况。
+     *
+     * @param productId 商品ID
+     * @return 抢购结果
+     */
+    @SaIgnore
+    @GetMapping("/purchase/{productId}")
+    @Operation(summary = "抢购商品")
+    public String purchase(@PathVariable Long productId) {
+        boolean success = productService.purchaseProduct(productId);
+        if (success) {
+            return "抢购成功";
+        } else {
+            return "库存不足，抢购失败";
+        }
+    }
+}    

src/main/java/com/laker/admin/module/ext/entity/Product.java

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+package com.laker.admin.module.ext.entity;
+
+import com.baomidou.mybatisplus.annotation.IdType;
+import com.baomidou.mybatisplus.annotation.TableId;
+
+public class Product {
+    @TableId(value = "id", type = IdType.AUTO)
+    private Long id;
+    private String name;
+    private int stock;
+
+    public Product() {
+    }
+
+    public Product(String name, int stock) {
+        this.name = name;
+        this.stock = stock;
+    }
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public int getStock() {
+        return stock;
+    }
+
+    public void setStock(int stock) {
+        this.stock = stock;
+    }
+}    

src/main/java/com/laker/admin/module/ext/mapper/ProductMapper.java

@@ -0,0 +1,11 @@
+package com.laker.admin.module.ext.mapper;
+
+import com.baomidou.mybatisplus.core.mapper.BaseMapper;
+import com.laker.admin.module.ext.entity.Product;
+import org.apache.ibatis.annotations.Update;
+
+public interface ProductMapper extends BaseMapper<Product> {
+    // 更新商品库存,防止超卖
+    @Update("update product set stock = stock - 1 where id = #{productId} and stock > 0")
+    int purchaseProduct(Long productId);
+}

src/main/java/com/laker/admin/module/ext/service/ProductService.java

@@ -0,0 +1,36 @@
+package com.laker.admin.module.ext.service;
+
+import com.laker.admin.module.ext.entity.Product;
+import com.laker.admin.module.ext.mapper.ProductMapper;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Service;
+
+@Slf4j
+@Service
+public class ProductService {
+
+    @Autowired
+    private ProductMapper productMapper;
+
+    //    @Transactional(rollbackFor = Exception.class, isolation = Isolation.READ_COMMITTED)
+    public boolean purchaseProduct(Long productId) {
+        log.info("开始购买商品，商品ID: {}", productId);
+        // 查询商品库存
+        Product product = productMapper.selectById(productId);
+        // 如果商品不存在或者库存不足，返回失败
+        if (product == null || product.getStock() <= 0) {
+            log.warn("商品不存在或者库存不足，商品ID: {}", productId);
+            return false;
+        }
+        // 更新商品库存,如果库存不足，更新失败
+        final int updateCount = productMapper.purchaseProduct(productId);
+        if (updateCount > 0) {
+            log.info("购买成功，商品ID: {}", productId);
+            return true;
+        } else {
+            log.warn("购买失败，商品ID: {}", productId);
+        }
+        return false;
+    }
+}

src/main/resources/db/migration/V2025.04.03__add_product.sql

@@ -0,0 +1,9 @@
+-- 商品表
+DROP TABLE IF EXISTS `product`;
+CREATE TABLE `product` (
+                           `id` bigint unsigned NOT NULL AUTO_INCREMENT,
+                           `name` varchar(100) DEFAULT NULL,
+                           `stock` bigint DEFAULT NULL,
+                           PRIMARY KEY (`id`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci;
+INSERT INTO product (id, name, stock) VALUES(1, 'aa', 100);

src/test/java/com/laker/admin/example/ThreadCounter.java

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+package com.laker.admin.example;
+
+import org.junit.jupiter.api.Test;
+
+public class ThreadCounter {
+    private int count = 0;
+
+    @Test
+    public void testThreadCounter() throws InterruptedException {
+        Runnable task = new Runnable() {
+            public void run() {
+                for (int i = 0; i < 10000; ++i) {
+                    count += 1;
+                }
+            }
+        };
+
+        Thread t1 = new Thread(task);
+        t1.start();
+
+        Thread t2 = new Thread(task);
+        t2.start();
+
+        t1.join();
+        t2.join();
+
+//        Assertions.assertThat(count).isEqualTo(20000);
+
+    }
+}